Method and system for recycling domestic greywater

ABSTRACT

The invention relates to a method and system for recycling domestic greywater. Greywater is drawn from a greywater waste pipe through an overflow pipe of a sanitary fixture, thereby, permitting greywater to be collected for reuse without the need for complicated and expensive retrofitting and/or reconfiguration of existing plumbing infrastructure. The system and method of the present invention can easily operate independently or be integrated with domestic utility systems to supply these utility systems with greywater.

FIELD OF THE INVENTION

The present invention pertains to the field of water conservation andmore specifically, to a method and system for recycling domesticgreywater.

BACKGROUND OF THE INVENTION

Water is considered a renewable resource, however, pressures on theresource are growing with increased demands on usage. As the readilyavailable supplies of fresh water are being used up, the importance ofwater conservation increases. Efforts to conserve water have extended todomestic household use, with much of the focus being on greywater whichcurrently contributes 75% of total wastewater flow to domestic sewers.

Greywater recycling is one method of water conservation. Greywater iswaste water that has the potential for reuse. To be considered greywaterthere must be no human/organic waste (feces) or toxic chemicals. Suchsources would include water from normal sink use and shower/bathtub use,or at times used wash water from clothes or dish washing units. Thispartially used water can be recycled for irrigation or used to flushtoilets. With partial filtration, or even with no treatment, greywatercan be a valuable and reusable resource.

Various systems have been developed for recycling domestic greywater.U.S. Pat. No. 7,913,331 describes an integrated system for collectingand diverting rainwater and greywater for toilet flushing. The describedsystem requires retrofitting of existing plumbing infrastructure and/orfixtures in order to integrate the system into the existing plumbingsystem of a home and further comprises numerous large and complicatedcomponents for its operation. In one example, U.S. Pat. No. 7,913,331describes a portable and easy to install version of the system, however,even this version requires retrofitting of the existing plumbing systemand/or sanitary fixtures in order to be operational.

There continues to be a need for methods and systems for recyclinggreywater that do not require complicated and expensive retrofitting ofthe existing plumbing system and that are adaptable for use withgreywater utility systems currently available on the market.

This background information is provided for the purpose of making knowninformation believed by the applicant to be of possible relevance to thepresent invention. No admission is necessarily intended, nor should beconstrued, that any of the preceding information constitutes prior artagainst the present invention.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a method and apparatus(the apparatus also referred to as a system) system for recyclingdomestic greywater. In accordance with an aspect of the presentinvention, there is provided a method for recycling domestic greywater,the method comprising: drawing greywater from a greywater waste pipe,directing the drawn greywater in a countercurrent direction through anoverflow pipe of a first sanitary fixture, and discharging the greywaterinto a second sanitary fixture or a greywater storage tank.

In accordance with another aspect of the invention, there is provided[[a]] an apparatus for recycling domestic greywater, the apparatuscomprising: a countercurrent greywater collector conduit having agreywater inlet end and a greywater discharge end, the inlet end beingadapted for insertion through an overflow pipe of a first sanitaryfixture and the discharge end being adapted for connection to a pump,wherein insertion through the overflow pipe allows greywater to be drawnfrom a greywater waste pipe that is in fluid communication with theoverflow pipe; when the pump is activated, the greywater flows throughthe greywater collector conduit in a direction counter to the normalflow of greywater within the overflow pipe; wherein the greywater drawnthrough the overflow pipe may be discharged into a second sanitaryfixture or into a greywater storage tank. The apparatus may also includea retainer for retaining the greywater collector conduit in positionwithin the overflow pipe. All references to a “greywater collectorconduit” in this document are directed to and imply a countercurrentgreywater collector conduit.

In accordance with another aspect of the invention, there is provided akit for recycling domestic greywater, the kit comprising: the systemaccording to the invention; and instructions for using the system.

BRIEF DESCRIPTION OF THE FIGURES

These and other features of the invention will become more apparent inthe following detailed description in which reference is made to theappended drawings.

FIG. 1 is a schematic of a bathtub overflow and drainage system withwhich the apparatus for recycling greywater can be used, according toembodiments of the present invention;

FIG. 2 is a perspective view of an embodiment of the apparatus forrecycling greywater installed in the bathtub overflow and drainagesystem of FIG. 1, according to the present invention;

FIG. 3 is a cross-sectional view of a sink drain system with which theapparatus for recycling greywater can be used, according to embodimentsof the present invention;

FIG. 4 is a schematic illustrating the installation of an apparatus forrecycling greywater, according to embodiments of the present invention;

FIG. 5 is a schematic of a system including a countercurrent greywatercollecting conduit installed in a typical household plumbingconfiguration wherein the greywater is discharged to a toilet tank,according to embodiments of the present invention;

FIG. 6 is a schematic of a system including a countercurrent greywatercollecting conduit for recycling greywater wherein the greywater isdischarged to a storage tank, according to embodiments of the presentinvention;

FIGS. 7(a) and (b) are perspective views of an apparatus for recyclinggreywater partially installed in an overflow pipe, according toembodiments of the present invention;

FIGS. 8(a) and (b) are perspective views of an apparatus for recyclinggreywater partially installed in an overflow pipe, according toembodiments of the present invention;

FIG. 9 is a flowchart illustrating one example of a feedback system fora system for recycling greywater, according to embodiments of thepresent invention; and

FIG. 10 is a perspective view of an apparatus for recycling greywaterinstalled on a bathtub, according to embodiments of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION Definitions

The term “greywater”, as used herein, refers to wastewater generatedfrom domestic activities, which can be recycled on-site for domesticreuse. Greywater, as used herein, may or may not require treatment fordomestic reuse.

The term “sanitary fixture”, as used herein refers to receptacles thatare attached to the interior systems of water pipes and seweragesystems. Sanitary fixtures include, for example, bathtubs, washstands,sinks, toilets, and urinals of various types.

The term “greywater storage tank”, as used herein refers to a storagetank of various shapes and sizes that is configured to hold greywater.

The term “domestic utility system”, as used herein refers to anintegrated system for distributing greywater from multiple sourceswithin a domicile, for example, for distribution on demand to at leastone application. For example, the greywater can be distributed to atleast one toilet tank for flushing the toilet.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs.

The method, according to embodiments of the present invention, comprisesdrawing greywater from a greywater waste pipe through an overflow pipeof a sanitary fixture, thereby, permitting greywater to be collected forreuse without the need for complicated and expensive retrofitting and/orreconfiguration of existing plumbing infrastructure. Furthermore, themethod can easily be integrated with domestic utility systems to supplythese utility systems with greywater.

The systems and apparatuses, according to embodiments of the presentinvention, require a minimal number of inexpensive components that areeasy to assemble and install in existing plumbing infrastructure,thereby avoiding the need for retrofitting and/or reconfiguring existingplumbing which can otherwise be complicated, expensive, and oftentimesrequiring expertise.

Method for Recycling Domestic Greywater

Referring to the drawings, in which like reference numerals identifyidentical or substantially similar parts throughout the several views,the present invention can be best understood by starting with a diagramof a standard overflow and drainage system commonly found in mostplumbing infrastructures. As shown in FIG. 1, a standard bathroomplumbing system 10 comprises an overflow pipe and greywater waste pipe40 through which greywater from a bathtub, for example, eventuallypasses to the sewer system. There are typically two access openings tothe greywater waste pipe 40, the drain opening 70 and the overflowopening 50. Greywater can flow through these respective openings 70 and50 by way of conduits that are each fluidly connected to the greywaterwaste pipe 40. These conduits are the drain pipe and the overflow pipe20, respectively. Similar drain systems can be found with other sanitaryfixtures. For example, FIG. 3 illustrates a similar drain system 10found with a sink. The sink drain system 10 comprises an overflowopening 50 fluidly connected to the greywater waste pipe 40 by way of anoverflow conduit 20. The drain opening 70 is fluidly connected to thegreywater waste pipe 40 by way of the drain pipe 30.

As illustrated in FIG. 2, the method, according to embodiments of thepresent invention, comprises drawing greywater from the greywater wastepipe 40 through the overflow pipe 20 of the sanitary fixture wherein thedrawn greywater is directed through a countercurrent greywater collectorconduit 60 positioned within the overflow pipe. While FIG. 2 shows theapparatus 80 installed on a bathtub 230, it will be apparent to thoseskilled in the art that the methods, systems and apparatuses of thepresent invention can be installed on other sanitary fixtures 30 thatcomprise similar drain systems 10, for example a sink.

The greywater is drawn through a countercurrent greywater collectorconduit 60 disposed through the overflow opening 50. In one embodiment,the greywater collector conduit 60 is connected to the suction conduitof a pump 100 which provides intake suction to draw up the greywaterthrough the overflow pipe/conduit 20 located above the greywater wastepipe 40. The intake greywater is then discharged from the dischargeconduit 170 of the pump 100 into a second sanitary fixture, for examplea toilet tank, or a greywater storage tank to be reserved and used asnecessary. In this way, the greywater is collected through an existingoverflow pipe/conduit 20 without the need for retrofitting and/orreconfiguration of the existing plumbing infrastructure. The greywatercollected in this way can then be recycled for domestic use.

In one embodiment, the collected greywater is discharged directly into atoilet tank for flushing the toilet (FIG. 5). In another embodiment, thecollected greywater is discharged into a greywater storage tank andreserved for domestic use, for example irrigation or toilet flushing, asneeded (FIG. 6). In a further embodiment, the greywater storage tank isintegrated with a domestic utility system for distributing greywaterfrom multiple sources and for multiple uses.

System for Recycling Domestic Greywater

Referring to FIGS. 7 and 8, the systems and apparatuses according toembodiments of the present invention comprises a countercurrentgreywater collector conduit 60 that is sized to fit through an overflowopening 50 of a sanitary fixture. In one embodiment, the greywatercollector conduit 60 is sized to fit through the overflow opening 50 ofa bathtub. In other embodiments, as shown in FIG. 3, the greywatercollector conduit 60 is sized to fit through the overflow opening 50 ofa sink. The greywater collector conduit 60 is of sufficient length andshape for disposal through the overflow opening 50 and the overflow pipeand/or conduit 20 to retrieve the greywater before it enters the citywaste water system. Plumbing infrastructure may vary in shape anddimension. Accordingly, the greywater collector conduit 60 issufficiently flexible to allow it to accommodate varying plumbinginfrastructures. The greywater collector conduit 60 can be made from anynumber of materials that provide both flexibility and durability. Forexample, without limiting the foregoing, the greywater collector conduit60 can be made from nylon, polyurethane, polyethylene, PVC, synthetic ornatural rubbers, or any combination.

As shown in FIG. 2, the inlet end of the countercurrent greywatercollector conduit 60 is adapted for insertion through the overflow pipe20 and the discharge end of the countercurrent greywater collectorconduit 60 is adapted for connection to the suction conduit of a pump100. In this way, greywater can be collected via the overflow pipe atthe juncture of the greywater waste pipe 40 before entering the buildingwaste water system and is discharged through the discharge conduit ofthe pump 100 directly into a toilet tank 130 (FIG. 5) or to a greywaterstorage tank 120 (FIG. 6).

In some embodiments, discharge of the greywater is controlled by aselector smart valve 220. Referring to FIG. 5, the selector smart valve220 is in fluid communication with the discharge conduit 170 and isconfigured to regulate discharge of the greywater. In some embodiments,the selector smart valve 220 may be fluidly connected to more than onewater source and be configured to coordinate the discharge of water fromthese sources on demand or as water is available. For example, as shownin FIG. 5, the selector smart valve 220 is in fluid communication withthe discharge conduit 170, a sink greywater conduit 270, and a citywater supply line 150. In this way, greywater from either the bathtub230 or the sink can be used to supply the toilet tank 130 whensufficient greywater is available, or fresh city water can be suppliedto supplement the water needed to supply the toilet tank 130 whengreywater is insufficient. In further embodiments, the selector smartvalve 220 comprises a manual override button that can be pressed at anytime to allow city fresh water to fill the toilet tank regardless of thetreated greywater supply.

The pump 100 can be configured to include controlling means to controlactivation of the pump 100 when greywater is available through theoverflow waste pipe. Referring to FIG. 2, for example, the pump 100 caninclude one or more sensors 90 for sensing fluid and/or pressure in theoverflow pipe where it connects to the greywater waste pipe 40 so thatthe pump 100 starts and activates drawing greywater through thegreywater collector conduit 60 only when sufficient greywater levels aredetected.

In other embodiments (FIG. 5), controlling means of the pump 100 can beconfigured to cooperatively communicate with corresponding sensors 210that detect fluid availability and/or levels in the greywater storagetank or toilet tank 130 in order to further coordinate the activationand discharge of greywater.

In some embodiments, the system 80 is controlled by way of aprogrammable controller powered by a power source, for example, a waterturbine AC/DC recharger 280, which source powers the pump 100 as well.In some embodiments, the pump 100 is part of a domestic utility system.In this way, the system of the present invention can operateindependently or be easily integrated into larger domestic utilitysystems.

The location of the pump 100 relative to the overflow opening 50 canvary as the system 80 can be adapted to accommodate a variety of pump100 locations. For example, as shown in FIG. 2, the pump 100 ispositioned at the bathtub overflow opening 50 or, in other embodiments,the pump 100 is disposed separate and away from the overflow opening 50.In embodiments where the pump 100 is disposed away from the overflowopening 50, the length of the greywater collector conduit 60 is adjustedto accommodate such distances. In this way, the system of the presentinvention is versatile and can be easily integrated into a variety ofdomestic utility systems.

In some embodiments, the system of the present invention furthercomprises a retainer 110 for positioning the greywater collector conduit60 within the overflow pipe and/or conduit 20 through the overflowopening 50. A retainer 110 according to one embodiment of the presentinvention is shown in FIGS. 7(a) and (b) to comprise a hook-likeattachment configured to overhang the lip of the overflow opening 50 andsized to wedge or hold the greywater collector conduit 60 into positionwithin the overflow opening 50. In other embodiments (FIGS. 8(a) and(b)), the retainer 110 is more permanently fixed to the overflow opening50 by utilizing the existing coverplate mounting bracket and screws 190.As shown in this embodiment, a t-bar 180 is fixed in place using theexisting coverplate screws 190 such that the t-bar 180 holds thegreywater collector conduit 60 into position within the overflow opening50. The retainer 110 can further be adapted to include a systemattachment means 200 to which the system 80, including for example thepump 100, in some embodiments, can be attached (FIGS. 8A AND 8B)

In other embodiments, alternative retaining means are contemplated forholding the system 80 in place overtop of the overflow opening 50. Forexample, suction cups, prongs for frictional security to a mountingbracket, as well as, but not limited to, a replacement bathtub overflowcoverplate can be used. A new mounting bracket or coverplate can even beforce-fitted into a circular sleeve on the overflow opening 50 with asnap on coverplate to hold the greywater collector conduit 60 insertedand positioned in place. In this way, installation of the system adaptsto and utilizes the existing plumbing infrastructure, thereby, avoidingany retrofitting and/or reconfiguration of the existing infrastructure.

Depending on where the greywater is collected from, the collectedgreywater may need to be filtered to remove debris before it can berecycled for reuse. Accordingly, in some embodiments, the system of thepresent invention further comprises a filter assembly 300 to filter thegreywater being drawn in through the inlet before the greywater isdischarged. In other embodiments, the system further comprises adisinfection assembly 320. The disinfection assembly 320 can include,for example, chlorination, ozonation, or ultra violet light 320 to treatthe greywater before discharging it to the storage tank or toilet tank.In some embodiments, the filtration assembly 300 and/or disinfectionassembly 320 is located at the pump 100 within the system 80 mountedovertop of the overflow opening 50. In other embodiments, the filtrationassembly 300 and/or disinfection assembly 320 is located at the storagetank 120.

As shown in FIG. 4, installation of the system of the present inventionis easy and does not necessarily require expert assistance ascomplicated retrofitting and/or reconfiguration of existing plumbinginfrastructure is avoided. The inlet end of the greywater collectorconduit 60 is disposed through the overflow opening 50 and fed throughthe overflow pipe and/or conduit 20 to access the greywater before thegreywater exits the greywater waste pipe 40. The discharge end of thegreywater collector conduit 60 is then connected to the suction conduitof a pump 100 to enable greywater to be drawn back before passingthrough the greywater waste pipe 40 and discharged directly to at leastone toilet tank or to a greywater storage tank.

It will be apparent that systems of the present invention can beinstalled on more than one sanitary fixture and networked to permitgreywater to be collected and recycled from more than one source. Thegreywater collected from these multiple sources, for example a sink anda bathtub, can be directly discharged to the same location. In someembodiments, the collected greywater can be discharged to at least onetoilet tank or to at least one greywater storage tank or a combinationof both.

Integration of Greywater Recycling System into Domestic Utility Systems

The system of the present invention is adaptable for integration into avariety of domestic utility systems as a means for supplying greywaterfor distribution by these larger systems. FIG. 6 illustrates oneembodiment of a domestic utility system that can operate in cooperationwith the system of the present invention. As shown, domestic utilitysystems can include a city water line 150 for supplementing greywaterlevels in the greywater storage tank 120 to ensure a sufficient watersupply for distribution. In this embodiment, greywater collected usingthe system of the present invention is discharged into the storage tank120 for distribution.

In other embodiments, as further illustrated in FIGS. 5 and 6, greywatercan be collected from more than one sanitary fixture, a bathtub 230using the system of the present invention and a sink 240. In theembodiment shown, the bathtub 230 has the system 80 of the presentinvention installed for recycling the greywater, the sink 240 has aU-joint 250 adapted with a valve 260 to redirect the greywater by a sinkgreywater conduit 270. The greywater from these two sources isdischarged and/or redirected to the toilet tank 130 (FIG. 5) or to atreated greywater storage tank 120 (FIG. 6). In some embodiments, thetreated greywater storage tank 120 comprises a pump for pumpinggreywater from the sink 240 to the storage tank 120.

Distribution of greywater can be controlled in these embodiments by aselector smart valve 220 which is activated to selectively distributewater from the treated greywater storage tank 120, bathtub 230, the sink240, or a city water line 150. For example, activation of the selectorsmart valve 220 is triggered when sensors 210 in the toilet tank 130sense that water levels are low. Activation of the selector smart valve220 causes the valve 220 to open to allow water to enter the toilet tank130 from the bathtub 230, the sink 240, the storage tank 120, or thecity water line 150 depending on sufficiency of the detected greywaterlevels. As shown, each of the greywater sources is in communication withthe selector smart valve 220 to provide a coordinated supply of water tothe toilet tank 130. The selector smart valve 220 can optionallycomprise a pump to actively pump water when activated. The system can becontrolled by way of a programmable controller 210 that is eitherremotely controlled or hardwired.

FIG. 9 further illustrates one embodiment of the feedback control systemof the domestic utility system illustrated in FIGS. 5 and 6.

The disclosures of all patents, patent applications, publications anddatabase entries referenced in this specification are herebyspecifically incorporated by reference in their entirety to the sameextent as if each such individual patent, patent application,publication and database entry were specifically and individuallyindicated to be incorporated by reference. Although the invention hasbeen described with reference to certain specific embodiments, variousmodifications thereof will be apparent to those skilled in the artwithout departing from the spirit and scope of the invention. All suchmodifications as would be apparent to one skilled in the art areintended to be included within the scope of the following claims.

I claim:
 1. An apparatus for recycling domestic greywater comprising: acountercurrent greywater collector conduit, a greywater drawing means,said countercurrent greywater collector conduit having a greywater inletend and a greywater discharge end, the inlet end being adapted forinsertion through an overflow pipe of a first sanitary fixture and thedischarge end being adapted for connection to the greywater drawingmeans, said apparatus configured wherein insertion of saidcountercurrent greywater collector conduit through the overflow pipeallows greywater to be drawn from a greywater waste pipe; saidcountercurrent greywater collector conduit being in fluid communicationwith the overflow pipe; wherein when the greywater drawing means isoperating, the greywater is drawn from said greywater waste pipe throughsaid countercurrent greywater collector conduit and flows countercurrentto the normal efflux direction of overflow greywater; and a retainer forretaining the countercurrent greywater collector conduit in positionwithin the overflow pipe; wherein the greywater drawn through saidcountercurrent greywater collector conduit is discharged into a secondsanitary fixture or a greywater storage tank.
 2. The apparatus accordingto claim 1, further comprising a pump, wherein the greywater drawingmeans is said pump, said pump having a suction conduit for connecting tothe greywater discharge end of the countercurrent greywater collectorconduit for greywater intake, and said pump having a discharge conduitfor connecting to the second sanitary fixture or to a greywater storagetank.
 3. The apparatus of claim 2, wherein the pump comprises one ormore sensors configured to detect when there is greywater available tobe drawn.
 4. The apparatus of claim 1 further comprising wherein theretainer has an attachment means, with said attachment means configuredto extend across apparatus
 80. 5. The apparatus according to claim 2,further comprising, a filter/disinfection assembly in fluidcommunication with the countercurrent greywater collector conduit,wherein greywater passes through the filter/disinfection assembly beforedischarging into the second sanitary fixture or greywater storage tank.6. The apparatus according to claim 4, further comprising, afilter/disinfection assembly in fluid communication with thecountercurrent greywater collector conduit, wherein greywater passesthrough the filter/disinfection assembly before discharging into thesecond sanitary fixture or greywater storage tank.
 7. The apparatusaccording to claim 6, further comprising, wherein the pump has one ormore sensors configured to detect when there is greywater available tobe drawn.
 8. The apparatus according to claim 7 further comprising, afeedback control unit, said feedback control unit comprising a selectorsmart valve to selectively distribute water to the second sanitaryfixture when said selector smart valve is activated by a sensor in thesecond sanitary fixture.
 9. The apparatus of claim 3 further comprisingwherein the retainer has an attachment means, with said attachment meansconfigured to extend across apparatus
 80. 10. The apparatus according toclaim 3, further comprising, a filter/disinfection assembly in fluidcommunication with the countercurrent greywater collector conduit,wherein greywater passes through the filter/disinfection assembly beforedischarging into the second sanitary fixture or greywater storage tank.11. The apparatus according to claim 3 further comprising, a feedbackcontrol unit, said feedback control unit comprising a selector smartvalve to selectively distribute water to the second sanitary fixturewhen said selector smart valve is activated by a sensor in the secondsanitary fixture.